In recent years, the use of reconstructive surgical implant devices has become a commonly elected surgical procedure. In some instances, the procedure is done to correct the patient's appearance for cosmetic reasons. More important, of course, is the use of this procedure to restore the patient to an appearance that approximates that which existed before other surgery or injury. One major use is, of course. postmastectomy breast reconstruction. At the same time, as the procedure is more common, some of the disadvantages of the procedure are causing more concern.
At the present time, there are three major types of mammary prostheses in use. These prostheses procedures include the autologous breast prosthesis, which is fashioned by grafting the patient's own abdominal fatty tissues, which are, of course, not synthetic. This procedure has the advantages of having a natural appearance and feel, and is completely biocompatible. Unfortunately, it is about three tinges as expensive as synthetic procedures, in part because of the need for two procedures. In addition, this procedure is a more involved surgical procedure with all of the attendant risks which that brings.
A second method or procedure currently employed is the use of a silicone envelope which has been filled with synthetic saline solution. This procedure is much less expensive than the first procedure and also offers appropriate biocompatibility of the filler. However, the use of a saline solution filled silicone envelope gives an unnatural appearance and feel. More important, perhaps, is the fact that the envelope is prone to capsular contracture or infection. For these reasons, this procedure is not truly acceptable and is to be avoided when an alternative procedure becomes available.
The third presently available method is the use of a silicone envelope which has been filled with synthetic silicone gel. This method is also relatively inexpensive like the second method, but has the additional advantage of providing a relatively good appearance and feel. This is the most popular procedure currently in use. However, this method also has some aspects which give rise to a concern. The filler is, potentially at least, a non-biocompatible filler and may even cause more problems, although studies are not at all complete in this area. Nevertheless, the envelope is also prone to capsular contracture or infection and is not totally acceptable for all persons under all circumstances.
Some improvements have been suggested in these methods. One suggestion is disclosed in U.S. Pat. No. 5,092,882, where a multiple compartment breast prosthesis is shown. In this patent, three separate compartments are filled with a conventional silicone gel. The separation of the compartments provides a better profile for the prosthesis. However, no suggestions are contained in this patent which would overcome the above described deficiencies with respect to the use of a non-biocompatible filler. Also, as previously noted, the envelope is prone to capsular contracture and/or infection.
Appearance is of primary concern, although not to the detriment of the health of the patient. U.S. Pat.No. 5,022,942 discloses a surgical prosthesis which has a textured exterior surface which has been formed from non-absorbent material which is substantially free from pores and interstices. Several methods of manufacturing the device are disclosed. Infection is stated to be avoided or reduced because the silicone rubber is non-absorbent to body fluids. This does not, however, change the concern which has been expressed above with respect to envelope compatibility with the human body.
Mother concern which the prior art has addressed is described in U.S. Pat. No. 5,026,394. In this reference, a reinforcement member is provided which is suggested to prevent or reduce capsular contracture due to scar tissue formation after implantation, resulting in maintenance of the desired profile and softness of the in, planted prosthesis. However, again there is no consideration of avoiding the problems described above which are caused by the use of conventional materials.
One patent which has offered a suggested filler material which has certain advantages over silicone oil is U.S. Pat. No. 5,067,965. In this patent, the use of certain salts of polyvinylpyrollidone is suggested because of its approximation of the x-ray absorption of normal breast tissue. The polymer is said to be bio-compatible. However, use of the polymer requires what appears to be close adjustment of the molecular weight, partly to adjust the x-ray or radio density properties, and partly to improve compatibility. It is noted that the reference explicitly teaches that the vast majority of the combinations suggested are completely excretable by the body and present no danger of foreign body reaction. The concern remaining is for the rest of the suggested combinations, and particularly those of higher molecular weight.
Accordingly, it is an object of the present invention to provide a reconstructive surgical in, plant device which avoids the use of a non-biocompatible filler and which employs an envelope which is not prone to capsular contracture and/or infection.
Mother object of this invention is to provide a device and method for its use as a reconstructive surgical implant device in which the envelope achieves compatibility with the patient.
Yet another object of the present invention is to provide a device which employs materials of construction which are free from the problems of silicone gels and other potentially non-biocompatible fillers, while not introducing concern for foreign body reaction and inability of tile body to remove the material.
Other objects will appear hereinafter.